Marine helical propellers are well known in marine-related industries. Marine helical propellers are typically designed to optimize the mechanical thrust force and generate fluid flow as an unnecessary byproduct. In industrial mixing applications, optimizing fluid flow may be one of the goals of an impeller system, and the mechanical thrust force may be an unnecessary byproduct. Therefore, an impeller that incorporates a typical marine-style helical blade design may not be designed to optimize fluid flow for mixing applications, which may limit the effectiveness of such impellers in some mixing applications.
In large oil refinery storage tanks or other large chemical storage tanks, it may be necessary to keep solid contaminant particles or other sediment suspended in the crude oil and its derivatives or other chemical or fluid, so that contaminants do not build up on the tank floor. In such tanks, one or more side-entry impellers are often used to help keep solid contaminants suspended in the crude oil and its derivatives, thereby keeping the tank floor clean.
In anaerobic digester tanks, it may be necessary to keep solid particles suspended in the fluid, in order to aid in the anaerobic digestion process. In such tanks, one or more top-entry impellers are often used to keep solid particles suspended in the fluid. Typically, a draft tube is used to allow a top-entry impeller to generate a mixing flow at the bottom of the anaerobic digester tank.